Quote:
Originally Posted by big dave
Every time I tried running at the track, I forgot to setup the timer to see how it compares to track timer. However, once I was able to download the video from my PDR, it confirms what you said, it's around .2 slower than what the track shows. What I did like though was that the mph matched up on the PDR to what my timeslip showed.
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I wish I could say the same about my mph matching, at the 1/4 mark anyway. My highest mph according to the track was 123. Unfortunately, I didn't do a PDR of that run, but I did the very next run, which was also my second highest mph. The timeslip shows 122.7 and the PDR shows an average of 126 between the timing lines (125 when I hit the first one and 127 when I hit the finish line). I recorded one more run on PDR that day and it was the same way. The slip had me at 121, but PDR shows 126 at the finish line (average of 125 between timing lines).
I didn't watch the videos while at the track, so I didn't know what they were showing at the time, but I told my dad that ZL1s trap higher than what I was getting on my slips through the 1/4, but oddly, the 1/8 was about right. All 7 runs that day were between 97 and 99 mph through the 1/8 and those speeds matched the PDR speeds perfectly if I paused the videos with the nose halfway between the 1/8 timing lines.
My dad had been complaining about his car not gaining the mph on the big end that it normally does and I told him mine wasn't either from all the slips I'd seen posted by others, so I was feeling a little skeptical about the track's 1/4 trap speeds being right, especially since the 1/8 speeds seemed right. Dad's car always gains 30 to 33 mph on the big end, but he was only getting around 27 that day.
I will definitely try to remember to PDR every pass next time and see if I can also do some more dash timers. I also want to play around with launch control. I couldn't use it last time. Apparently if you set the tire pressure so low that the low air light comes on, all the PTM stuff is disabled. No line lock, no launch control, nothing. Hopefully I can get a better feel for which trap speed to believe or maybe they'll match next time. Preferably the track will show what PDR did.
And maybe I'll learn that more air equals more grip with the stock rubber and I'll even get better times.
